Mobile telephone apparatus

• US 20050014520A1
• Filed: 12/12/2002
• Published: 01/20/2005
• Est. Priority Date: 12/14/2001
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Noda, Koji, Kimura, Yasuhisa
• Granted Patent: US 7,577,452 B2
• Time in Patent Office: Days
• US Class Current: 455/502
• CPC Class Codes: H04B 7/00 Radio transmission systems, i.e. using radiation field H04B10/00, H04B15/00 take precedence
• CPC Class Codes: H04B 7/0822 according to predefined selection scheme
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 52/287 when the channel is in stand-by

Abstract

The invention provides a cell phone which shows good receiving sensitivity even in a state where synchronization with a base station is not provided, such as power-on and detection of a dead space. The invention alternately switches between a plurality of antennas a predetermined number of times per fixed time predetermined in accordance with the number of perch channels in a state where synchronization with a base station is not provided, and sets an antenna whose mean value of the receiving level of each of these antennas is the highest as an antenna to be used subsequently, that is, an antenna to open a control channel.

Claims

1. A cell phone comprising:

switching means for alternately switching between a plurality of antennas a predetermined number of times per predetermined fixed time in a state where synchronization with a base station is not provided,

wherein said cell phone selects an antenna whose sum of the receiving levels is the highest among the antennas selected by said switching means, and selects a channel whose receiving level is the highest, and

wherein said cell phone, while in a state where synchronization with a base station is provided, alternately switches between said antennas with a predetermined timing in synchronization with said selected channel, detects a receiving level in the state, and uses an antenna whose receiving level is the highest.

2. The cell phone according to claim 1,

wherein said predetermined fixed time is a fixed time determined in accordance with the number of perch channels.

3. The cell phone according to claim 1,

wherein, in a state where synchronization with the base station is not provided at power-on, said predetermined fixed time is sufficiently longer than the period where said switching means alternately switches between the antennas in a state where synchronization with the base station is provided.

4. The cell phone according to claim 1,

wherein, in a state where synchronization with the base station is not provided on detection of a dead space, said predetermined fixed time is sufficiently longer than the period where said switching means alternately switches between the antennas in a state where synchronization with the base station is provided.